[dawidpotocki]

It's really hard for me to take UX people seriously that believe that such text style is okay. My eyesight is good but my eyes still get tired reading such thin font, even the "bold" text is too thin. I shouldn't have to turn on Reader Mode to be able to read your website.

Don't touch my browser font, font size (no arbitrary px, use rem/em with main text at least 1rem) and font weight. How hard is this?

[caspar]

In Firefox, you can go to Settings >> Fonts >> Advanced >> Untick "Allow pages to choose their own fonts, instead of your selections above", then you'll never have this problem again (though you sometimes will end up with others, such as icon-fonts not rendering as icons, and missing out on meta-discussions around poor font choices).